Gas turbine engine rotors require balancing in order to avoid operational problems due to vibrations. Severe vibrations also reduce the effective life of the rotor components.
Generally, the balancing of rotors is done by the addition of discrete balance weights. Such weights are often attached to a carrier serving no other function that to carry the weights. The weights may also be inserted in grooves at the root of rotor blades. The carrier in the first solution provides undesirable extra weight, while the second solution adds stress concentrations in the rotor components due to the grooves and also adds complexity and weight because of the retaining means usually necessary to retain the balance weights.
Balancing can also be done by the removal of material from selected locations. However, direct removal of material from the rotor disk adds stress concentrations to the detriment of the rotor.
Accordingly, there is a need for simple means to balance a rotor assembly without adding unnecessary weight or removing material from components of the rotor assembly.